"I know he's dying to get back, and we're dying to have him back," Luhnow said. "The fact we had a winning month last month [15-14] without George Springer is not something that we would have probably expected, because he's a big part of our offense and our defense.
"He's a big part of our clubhouse, and I want him back. Our trainers are working hard, he's working hard, and we're hoping we'll get at least a couple of weeks, if not more."
In addition, Luhnow said that outfielder Alex Presley has been activated from the disabled list after missing nearly two months with a strained oblique, but he's likely still a few days from game action. With rosters expanded, the Astros could activate Presley without taking another roster spot.
Brian McTaggart is reporter for MLB.com and writes an MLBlog, Tag's Lines. Follow @brianmctaggart on Twitter. This story was not subject to the approval of Major League Baseball or its clubs.